THE NEXT ICE AGE - NOW!

May be contributing to present-day
glacial melt
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21 Jan 08 - A powerful volcano erupted under the West Antarctic ice
sheet around 2,000 years ago and might still be active today, say
scientists from The British Antarctic Survey (Bas), who reported their
finding in the journal Nature Geoscience.

The finding raises the question whether this or other sub-glacial
volcanoes may have melted so much ice that global sea levels were
affected.

The explosive event -- rated "severe" to
"cataclysmic" on an international scale of volcanic force --
punched a massive breach in the ice sheet and spat out a plume some
12,000 metres (eight miles) into the sky, they calculate.

"The ash and the sulphuric acid and so on would have been
blasted out mixed up with steam from the melting ice," said David
Vaughan of Bas, who worked on the project.

But volcanoes which are not conspicuously active at present may also
be generating heat under the ice.

Most of Antarctica is seismically stable. But its western part lies
(the part where the ice is melting today) on a rift in Earth's crust
that gives rise to occasional volcanism and geothermal heat, occurring
on the Antarctic coastal margins.

The Hudson Mountains where the volcano was discovered lie close to
Pine Island Glacier, one of the West Antarctic glaciers whose flow has
accelerated in recent years. "This one is probably producing heat
and melt water," said Professor Vaughan. "That would end up
under Pine Island Glacier and could be thinning it."

"The flow of this glacier towards the coast has speeded up in
recent decades, and it may be possible that heat from the volcano has
caused some of that acceleration," Vaughan said.